In both acute-care medicine and as part of delivering a general anesthetic for an operative procedure it is often necessary to insert a breathing tube into the airway of a living organism, most often a human, but in some cases this can also apply to pets, livestock and other animals. This procedure is called endotracheal intubation. A variety of tools exist for performing this procedure, which is usually performed by highly trained professionals in a hospital, or pre-hospital setting. Most intubations are performed with direct laryngoscopy, using a device called a direct laryngoscope, which incorporates a curved or straight blade. The laryngoscope is inserted into the patient's mouth and throat by the clinician who is generally standing at the patient's head. The laryngoscope blade controls the tongue and other internal structures to help directly visualize the vocal cords (glottic inlet). The vocal cords mark the entry point to the wind pipe (trachea) and lungs and represent the target destination through which the breathing tube (endotracheal tube) is advanced.
When intubating a human, the goal is to place an endotracheal tube between the vocal cords (the glottic inlet) into the upper trachea to allow oxygen to be supplied to the lungs. It is preferable that the vocal cords be seen during intubation as they are the best guide to entry into the trachea and lungs, as opposed to incorrect entry to the esophagus and stomach. Unrecognized failure to correctly place an endotracheal tube into the trachea can result in a failure of oxygenation, and the patient's death.
In expert hands, endotracheal intubation using a direct laryngoscope will be easy 95% of the time. A real challenge remains in that it takes 50 or more intubations to achieve a 90% success rate. In an attempt to deal with this learning curve issue and to help manage difficult cases, so-called ‘alternative intubation’ devices have been developed. Some such scopes feature an “L”-shaped blade and use fiber- or video-optics for visualization. Using these devices, visualization of the vocal cords is often made easier but actual delivery of the breathing tube (endotracheal tube, ETT) between the cords into the windpipe (trachea) of the patient often remains difficult. When using these devices, not infrequently, during navigation of the ETT to and through the vocal cords, forward advancement of the ETT can be impeded by ‘hang-up’ on the right vocal cord. In addition, sporadic cases of trauma to the soft palate have been reported.
In another prior art device, a rounded tubular “J”-shaped blade was used incorporating a tube delivery channel to help with tube delivery. However, while the delivery channel was an attempt to deal with the challenges of tube placement, success was often impaired because: (a) the rounded (tubular) blade was too narrow to control the tongue and soft tissues well, so that one could often ‘get lost’ and not see the target vocal cords, and (b) the tube emerged from the delivery channel heading in an angle that often resulted in the tube being directed incorrectly into the esophagus and not the trachea.
There is a continued need for an intubation device for use by clinicians that is highly reliable, relatively easy to use and is able to link visualization of vocal cords directly with endotracheal tube placement.